The Free On-line Dictionary of Computing (30 December 2018):

Berkeley Software Distribution
4.2BSD
4.3BSD
Berkeley 4.2
Berkeley Unix
BSD
BSD Unix

    (BSD) A family of Unix versions developed
   by Bill Joy and others at the University of California at
   Berkeley, originally for the DEC VAX and PDP-11
   computers, and subsequently ported to almost all modern
   general-purpose computers.  BSD Unix incorporates paged
   virtual memory, TCP/IP networking enhancements and many
   other features.

   BSD UNIX 4.0 was released on 1980-10-19.  The BSD versions
   (4.1, 4.2, and 4.3) and the commercial versions derived from
   them (SunOS, ULTRIX, Mt. Xinu, Dynix) held the
   technical lead in the Unix world until AT&T's successful
   standardisation efforts after about 1986, and are still widely
   popular.

   See also Berzerkeley, USG Unix.

   (2005-01-20)